OpenCPN does not come with charts, however there are many Chart Sources, and it does come with a Background Map (GSHHS Low Res) installed which shows the Continents. This GSHHG Basemap is always displayed, regardless of chart groups, and it can be improved with a High Resolution GSHHG Background Map.
For more detail see High Resolution GSHHG Background Map.
Charts are a complex subject. OpenCPN can read BSB, S-57 unencrypted and early CM93 charts natively. There are a number of OpenCPN Chart plugins which enable reading specialized and encrypted chart sets.
Having accurate and current charts is important for safe navigation. The USA provides free NOAA Charts as do many other countries. The built-in ChartDownloader Tool will download free (S-57) NOAA ENC digital and RNC raster Charts which OpenCPN can read natively without use of a Plugin.
There are basically three excellent ways to install Charts:
Getting started using OpenCPN consists of 3 basic steps:
Completing these 3 steps will get you started and allow you to check out the program.
If you still have questions there is a large supportive OpenCPN community in this Cruisers Forum.